# Endangered and Threatened Wildlife and Plants; Endangered Status for the Ozark Hellbender Salamander > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2011-25690 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** October 6, 2011 - **Citation:** 76 FR 61956 ## Text DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R3-ES-2009-0009; MO 92210-0-0008-B2] RIN 1018-AV94 Endangered and Threatened Wildlife and Plants; Endangered Status for the Ozark Hellbender Salamander AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine endangered status under the Endangered Species Act of 1973 (Act), as amended, for the Ozark Hellbender ( Cryptobranchus alleganiensis bishopi ), a subspecies found in northern Arkansas and southern Missouri. This final rule implements the Federal protections provided by the Act for this species. We have also determined that the designation of critical habitat for the Ozark Hellbender is not prudent. The final rule for the CITES Appendix III listing for the Ozark and Eastern Hellbender is being published concurrently in today's Federal Register . DATES: This final rule is effective November 7, 2011. ADDRESSES: The final rule is available on the Internet at http://www.regulations.gov and at the Columbia Missouri Ecological Services Field Office. Comments and materials received, as well as supporting documentation used in the preparation of this rule, will be available for public inspection, by appointment, during normal business hours at: U.S. Fish and Wildlife Service, Columbia Missouri Ecological Services Field Office, 101 Park De Ville Dr., Suite A, Columbia, MO 65203; telephone: 573-234-2132; facsimile: 573-234-2181. FOR FURTHER INFORMATION CONTACT: Charles Scott, Field Supervisor, at the U.S. Fish and Wildlife Service, Columbia Missouri Ecological Services Field Office (see ADDRESSES section). If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339. SUPPLEMENTARY INFORMATION: Background The Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq. ) is a law that was passed to prevent extinction of species by providing measures to help alleviate the loss of species and their habitats. Before a plant or animal species can receive the protection provided by the Act, it must first be added to the Federal Lists of Threatened and Endangered Wildlife and Plants; section 4 of the Act and its implementing regulations at 50 CFR part 424 set forth the procedures for adding species to these lists. We published a proposed rule (75 FR 54561) to list the Ozark Hellbender ( Cryptobranchus alleganiensis bishopi ) as endangered under the Endangered Species Act, as amended (Act; 16 U.S.C. 1531 et seq. ) on September 8, 2010, with a 60-day public comment period. Previous Federal Action Federal actions for this species prior to September 8, 2010, are outlined in our proposed rule for this action (75 FR 54561). We implemented the Service's peer review process and opened a 60-day comment period to solicit scientific and commercial information on the species from all interested parties following publication of the proposed rule. Because collection for trade is considered a primary threat, we coordinated with our Division of Management Authority to develop, concurrent with that proposal, a proposal to list the Ozark Hellbender as well as the Eastern Hellbender in Appendix III of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) (75 FR 54579). The final rule for the CITES Appendix III listing is being published concurrently in today's Federal Register . Species Description The Ozark Hellbender is a large, strictly aquatic salamander endemic to streams of the Ozark Plateau in southern Missouri and northern Arkansas. Its dorso-ventrally flattened body form enables movements in the fast-flowing streams it inhabits (Nickerson and Mays 1973a, p. 1). Ozark Hellbenders have a large, keeled tail and tiny eyes. An adult may attain a total length of 11.4 to 22.4 inches (in) (29 to 57 centimeters (cm)) (Dundee and Dundee 1965, pp. 369-370; Johnson 2000, p. 41). Numerous fleshy folds along the sides of the body provide surface area for respiration (Nickerson and Mays 1973a, pp. 26-28) and obscure their poorly developed costal grooves (grooves in the inner border of the ribs; Dundee 1971, p. 101.1). Ozark Hellbenders are distinguishable from Eastern Hellbenders ( Cryptobranchus alleganiensis alleganiensis ) by their smaller body size, dorsal blotches, increased skin mottling, heavily pigmented lower lip, smooth surfaced lateral line system, and reduced spiracular openings (openings where water is expelled out of the body) (Grobman 1943, p. 6; Dundee 1971, p. 101.3; Peterson et al. 1983, pp. 227-231; LaClaire 1993, pp. 1-2). Despite these distinguishing characteristics, the two subspecies are not easily or readily distinguishable absent the presence of both subspecies or when encountered outside of their subspecies' range. Taxonomy The Ozark Hellbender was originally described as Cryptobranchus bishopi by Grobman (1943, pp. 6-9) from a specimen collected from the Current River in Carter County, Missouri. Based on the slight morphological and ecological variation within the genus Cryptobranchus, Dundee and Dundee (1965, pp. 369-370) determined subspecific status for Ozark and Eastern hellbenders as within the hellbender, C. alleganiensis complex sensu lato (which means, “in the broad sense” and is used when two subspecies are derived from a single species within a broader context). Subsequent genetic analyses by Merkle et al. (1977, pp. 550-552) and Shaffer and Breden (1989, pp. 1017-1022) supported the classification of the Ozark and Eastern hellbender as subspecies. In 1991 Collins (1991, pp. 42-43) attempted to revive the designation of C. bishopi, due to the lack of intergradation between the Eastern and Ozark Hellbenders, primarily a result of the taxa occurring in separate, nonoverlapping geographic areas (Dundee 1971, p. 101.1). However, despite some phenotypic and genetic differences between Ozark and Eastern hellbenders (Grobman 1943, pp. 6-9; Dundee and Dundee 1965, p. 370; Dundee 1971, p. 101.1; Routman 1993, pp. 410-415; Kucuktas et al. 2001, p. 127), the suggestion to elevate Ozark and Eastern hellbenders to species status was never accepted by other taxonomists (Crother et al. 2008, p. 15). We will continue to use the nomenclature C. a. bishopi for the Ozark Hellbender, which is the taxonomy currently recognized by the Committee on Standard English and Scientific Names (Crother et al. 2008, p. 15). Although discussion continues over the taxonomic status of the Ozark Hellbender, the designation of the Ozark Hellbender as a species or subspecies does not affect its qualification for listing under the Act (16 U.S.C. 1531 et seq. ). Habitat and Life History Eastern and Ozark hellbenders are similar in habitat selection, movement, and reproductive biology (Nickerson and Mays 1973a, pp. 44-55). Published works on the Eastern Hellbender provide insights into Ozark Hellbender ecology. Adult Ozark Hellbenders are frequently found beneath large rocks, typically limestone or dolomite, and in moderate to deep (less than 3 feet (ft) to 9.8 ft (less than 1 meter (m) to 3 m)), rocky, fast-flowing streams in the Ozark Plateau (Johnson 2000, p. 42; Fobes and Wilkinson 1995, pp. 5-7). In spring-fed streams, Ozark Hellbenders will often concentrate downstream of the spring, where there is little water temperature change throughout the year (Dundee and Dundee 1965, p. 370). Adults are nocturnal, remaining beneath cover during the day and emerging to forage at night, primarily on crayfish. They are diurnal during the breeding season (Nickerson and Mays 1973a, pp. 40-41; Noeske and Nickerson 1979, pp. 92, 94). Ozark Hellbenders are territorial and will defend occupied cover from other hellbenders (Nickerson and Mays 1973a, pp. 42-43). This species migrates little throughout its life. For example, one tagging study revealed that 70 percent of marked individuals moved less than 100 ft (30 m) from the site of original capture (Nickerson and Mays 1973b, p. 1165). Home ranges average 91.9 square (sq) ft (28 sq m) for females and 265.7 sq ft (81 sq m) for males (Peterson and Wilkinson 1996, p. 126). Hellbenders are habitat specialists that depend on consistent levels of dissolved oxygen, temperature, and flow (Williams et al. 1981, p. 97). The lower dissolved-oxygen levels found in warm or standing water do not provide for the hellbender's respiratory needs. In fact, hellbenders have been observed rocking or swaying in still, warm water (Williams et al. 1981, p. 97) to increase their exposure to oxygen. Hutchison and Hill (1976, p. 327) found that the hellbender exhibits a preferred mean water temperature of 52.9 °F (11.6 °C), 63.9 °F (17.7 °C), and 71.1 °F (21.7 °C) for individuals acclimatized to temperatures of 41 °F (5 °C), 59 °F (15 °C), and 77 °F (25 °C), respectively. Hutchison et al. (1973, p. 807) found the mean critical thermal maxima (the temperature at which animals lose their organized locomotory ability and are unable to escape from conditions that would promptly lead to their death) of Ozark Hellbenders was 90.9 °F (32.7 °C) at 41 °F (5 °C) acclimation, 91.2 °F (32.9 °C) at 59 °F (15 °C), and 97.7 °F (36.5 °C) at 77° F (25 °C). Hellbenders are long-lived, capable of living 25 to 30 years in the wild (Peterson et al. 1983, p. 228). Hellbenders may live up to 29 years in captivity (Nigrelli 1954, p. 297). Individuals mature sexually at 5 to 8 years of age (Bishop 1941, pp. 49-50; Dundee and Dundee 1965, p. 370), and males normally mature at a smaller size and younger age than females. Female hellbenders are reported to be sexually mature at a total length of 14.6 to 15.4 in (37 to 39 cm), or at an age of approximately 6 to 8 years (Nickerson and Mayes 1973a, p. 54; Peterson et al. 1983, p. 229; Taber et al. 1975, p. 638). Male hellbenders have been reported to reach sexual maturity at a total length of 11.8 in (30 cm), or at an age of approximately 5 years (Taber et al. 1975, p. 638). Breeding generally occurs between mid-September and early October (Johnson 2000, p. 42). Males prepare nests beneath large flat rocks or submerged logs. Ozark Hellbenders mate via external fertilization, and males will guard the fertilized eggs from predation by other hellbenders (Nickerson and Mays 1973a, pp. 42, 48). Clutch sizes vary from 138 to 450 eggs per nest (Dundee and Dundee 1965, p. 369), and eggs hatch after approximately 80 days (Bishop 1941, p. 47). Larvae and small individuals hide beneath small stones in gravel beds or under large rocks, similar to those occupied by adults (Nickerson and Mays 1973a, p. 12; LaClaire 1993, p. 2). Although there is little information on the diet of larval hellbenders, it is generally believed that aquatic insects comprise their primary food source. In one of the few studies on larval diet, Pitt and Nickerson (2006, p. 69) found that the stomach of a larval Eastern Hellbender from the Little River in Tennessee exclusively contained aquatic insects. During or shortly after eggs are laid, males and females may prey upon their own and other individuals' clutches. Most hellbenders examined during the breeding season contain between 15 and 25 eggs in their stomachs (Smith 1907, p. 26). Males frequently regurgitate eggs (King 1939, p. 548; Pfingsten 1990, p. 49), and females sometimes eat their own eggs while ovipositing (laying) them (Nickerson and Mays 1973a, p. 46). Topping and Ingersol (1981, p. 875) found that up to 24 percent of the gravid (egg-bearing) females examined from the Niangua River in Missouri retained their eggs and eventually reabsorbed them. Range Ozark Hellbenders are endemic to the White River drainage in northern Arkansas and southern Missouri (Johnson 2000, pp. 40-41), historically occurring in portions of the Spring, White, Black, Eleven Point, and Current Rivers and their tributaries (North Fork White River, Bryant Creek, and Jacks Fork) (LaClaire 1993, p. 3). Currently, populations of Ozark Hellbenders are known to occur in the North Fork of the White River, the Eleven Point River, and the Current River. The other subspecies of hellbender, the Eastern Hellbender, occurs in central and eastern Missouri (in portions of the Missouri drainage in south-central Missouri and the Meramec (Mississippi drainage)), but its range does not overlap with that of the Ozark Hellbender. The Eastern Hellbender's range extends eastward to New York, Georgia, and the States in between. Population Estimates and Status Evidence indicates Ozark Hellbenders are declining throughout their range (Wheeler et al. 2003, pp. 153, 155), and no populations appear to be stable. At the request of the Saint Louis Zoo's Wildcare Institute, the Conservation Breeding Specialist Group (CBSG) facilitated a Population and Habitat Viability Analysis (PHVA) for Ozark and Eastern Hellbenders in August 2006. Thirty workshop participants explored threats to hellbender populations and developed management actions aimed at understanding and halting their decline. Using the software program Vortex (v9.61), the CBSG team prepared and presented a baseline model for hellbender populations and worked through the input parameters with the participants to optimize the model and determine current and projected mean population sizes for all current populations in 75 years (Briggler et al. 2007, pp. 8, 80-86). The results of the model are presented in the river-specific population accounts below. A description of what we know about Ozark Hellbender populations follows, including current population estimates from the hellbender PHVA (Briggler et al. 2007, pp. 83-84). White River—There are only two Ozark Hellbender records from the main stem of the White River. In 1997, an Ozark Hellbender was recorded in Baxter County, Arkansas (Irwin 2008a, pers. comm.). No hellbenders were found during a 2001 survey of the lower portion of the White River, but in 2003, an angler caught a specimen in Independence County, Arkansas (Irwin 2008a, pers. comm.). We do not know whether a viable population exists (or whether hellbenders are able to exist) in the main stem of the White River or if the individuals captured are members of a relic population that was separated from the North Fork White River population by Norfork Reservoir. Much of the potentially occupied hellbender habitat was destroyed by the series of dams constructed in the 1940s and 1950s on the upper White River, including Beaver, Table Rock, Bull Shoals, and Norfork Reservoirs. North Fork White River—The North Fork White River (North Fork) historically contained a considerable Ozark Hellbender population. In 1973, results of a mark-recapture study indicated that there were approximately 1,150 hellbenders within a 1.7-mile (mi) (2.7-kilometer (km)) reach of the North Fork in Ozark County, Missouri, with an estimated density of one individual per 26.2 to 32.8 sq ft (8 to 10 sq m; Nickerson and Mays 1973b, p. 1165). Ten years later, hellbender density in a 2.9-mi (4.6-km) section of the North Fork in the same county remained high, with estimated densities between one per 19.7 sq ft (6 sq m) and one per 52.5 sq ft (16 sq m; Peterson et al. 1983, p. 230). Individuals caught in this study also represented a range of lengths from 6.8 to 21.7 in (172 to 551 millimeters (mm)), indicating that reproduction was occurring in this population, and most individuals measured between 9.8 and 17.7 in (250 and 449 mm). In a 1992 qualitative study in Ozark County, Missouri, 122 hellbenders were caught during 49 person-hours of searching the North Fork (Ziehmer and Johnson 1992, p. 2). Those individuals ranged in length from 10 to 18 in (254 to 457 mm), and no average length was included in that publication. Until the 1992 study, the North Fork population appeared to be relatively healthy. However, in a 1998 study of the same reach of river that was censused in 1983 (Peterson et al. 1983, pp. 225-231) and that used the same collection methods, only 50 hellbenders were captured (Wheeler et al. 1999, p. 18). These individuals ranged in length from 7.9 to 20.0 in (200 to 507 mm), with most measuring between 15.7 and 19.7 in (400 and 500 mm), and the average length was significantly greater than the average length of those collected 20 years earlier (Wheeler 1999, p. 15). This shift in length distribution was not a result of an increase in maximum length of individuals; instead, there were fewer individuals collected in the smaller size classes. As a way to compare relative abundance of hellbenders in the late 1990s to historic numbers, Wheeler et al. (2003, pp.152-153) obtained raw data used in the Peterson et al. (1983) study to calculate numbers of individuals caught per day. Other Ozark Hellbender population studies not included in that conversion are converted here for further comparison of relative abundance between historic and more recent studies (Ziehmer and Johnson 1992, pp. 1-5). For comparison purposes, one search day is defined as 8 hours of searching by 3 people (or 24 person-hours). However, converting person-hours to a search day metric may underestimate actual search effort and overestimate relative hellbender abundance as person-hours usually only include time spent in the water searching (as opposed to total number of hours spent on the river). It should also be noted that because search effort was not standardized among all studies, comparison of hellbender captures per search day is a general, rather than a quantitative, comparison. Using this metric for the North Fork, approximately 55 hellbenders were caught per search day in 1983 (Peterson et al. 1983, pp. 225-231). In 1992, 60 hellbenders per search day were caught (Ziehmer and Johnson 1992, p. 2), and in 1998, 17 hellbenders per search day were caught (Wheeler 2003, p. 153). Another comparison of Ozark Hellbenders captures between historic and recent years provides further evidence of a decline. A 16.2-mi (25-km) section of stream in the North Fork (overlapping with some sites sampled in the previous studies) was surveyed during 1969-1979 and again during 2005-2006 (Nickerson and Briggler 2007, pp. 212-213). Between 1969 and 1979, researchers caught 8 to 12 hellbenders per hour (64 to 96 hellbenders per search day); whereas in 2005 and 2006 researchers averaged 0.5 hellbenders per hour (4 hellbenders per search day) (Nickerson and Briggler 2007, p. 213). In 2006, hellbender experts estimated the current population in the North Fork to be 200 individuals (Briggler et al. 2007, p. 83). The North Fork had been considered the stronghold of the species in Missouri, and the populations inhabiting this river were considered stable by Ziehmer and Johnson (1992, p. 3) and LaClaire (1993, pp. 3-4). However, the studies cited above indicate that these populations now appear to be experiencing declines similar to those in other streams. The collection of young individuals has become rare, indicating that there is little recruitment. Although Briggler (2011c, pers. comm.) occasionally found some younger hellbenders in this river during surveys between 2005 and 2010, no larvae have been found despite extensive effort. In species such as the hellbender, which are long lived and mature at a relatively late age, detecting declines related to insufficient recruitment can take many years, as recruitment under healthy population conditions is typically low (Nickerson and Mays 1973a, p. 54). Based on the comparisons of relative abundance and lack of observed recruitment, it appears that a severe decline has occurred in the North Fork. Bryant Creek— Bryant Creek is a tributary of the North Fork in Ozark County, Missouri, which flows into Norfork Reservoir. Ziehmer and Johnson (1992, p. 2) expected to find Ozark Hellbenders in this stream during an initial survey, but none were captured or observed after 22 person-hours (0.9 search days). This apparent absence of the species conflicted with previous reports from Missouri Department of Conservation (MDC) personnel and an angler who reported observations of fairly high numbers of hellbenders in Bryant Creek during the winter months (Ziehmer and Johnson 1992, p. 3). A subsequent survey of the creek resulted in the capture of six hellbenders (Wheeler et al. 1999, p. 7) and confirmed the existence of a population in this tributary, at least through 1998. This population, however, is isolated from the other North Fork White River populations by the Norfork Reservoir, which could contribute to this population's apparent small size due to fragmentation of habitat. During MDC surveys conducted in 2007, no individuals were found in areas where the six individuals were found in 1998. However, five individuals were found in areas of Bryant Creek that were not surveyed in 1998. This population has been historically low and is not considered to be viable (Briggler 2008b, pers. comm.). Black River—There is one documented record of an Ozark Hellbender in the Black River above its confluence with the Strawberry River on the Independence-Jackson County line (Arkansas) in 1978 (Irwin 2008a, pers. comm.). Portions of the Black River in Missouri were surveyed in 1999 by researchers at Arkansas State University, but no hellbenders were observed (Wheeler et al. 1999, p. 18). Currently, the Black River does not appear to have conditions suitable for Ozark Hellbenders, although it may have been occupied before intensive agriculture was initiated in the area (Irwin 2008b, pers. comm.). The Black River is presumed to be part of the historical range of the subspecies, because Ozark Hellbenders have been documented in several of its tributaries, including the Spring, Current, and Eleven Point rivers (Firschein 1951, p. 456; Trauth et al. 1992, p. 83). In 2004, MDC surveyed areas in Missouri that had been searched in 1999 (Wheeler et al. 1999, p. 18), as well as areas not searched in 1999 that had anecdotal reports of hellbenders. No hellbenders were found during this 2-day survey. The habitat was considered less than ideal because it was predominantly composed of igneous rocks, which lack the cracks and crevices necessary for hellbender inhabitance. Parts of the Black River, with suitable dolomite rock, might have contained a small population at one time (Briggler 2008b, pers. comm.). Spring River—The Spring River, a tributary of the Black River, flows from Oregon County, Missouri, south into Arkansas. Ozark Hellbender populations have been found in the Spring River near Mammoth Spring in Fulton County, Arkansas (LaClaire 1993, p. 3). In the early 1980s, 370 individuals were captured during a mark-recapture study along 4.4-mi (7-km) of stream south of Mammoth Spring (Peterson et al. 1988, p. 293). Hellbender density at each of the two surveyed sites was fairly high (approximately one per 75.5 square (sq) ft (23 sq m) and one per 364 sq ft (111 sq m), respectively). These individuals were considerably larger than hellbenders captured from other streams during the same time period, with 74 percent of Spring River hellbenders having a total length of more than 17.7 in (450 mm), with a maximum length of 23.6 in (600 mm) (Peterson et al. 1988, p. 294). Although other factors may be involved in the observed length differences, it has been hypothesized that Spring River populations are genetically distinct from other hellbender populations. This speculation was upheld by the conclusions of a genetic study of the populations in the Spring, Current, and Eleven Point rivers (Kucuktas et al. 2001, pp. 131-135). In 1991, surveyors searched 10 sites for hellbenders along a 16.2-mi (26-km) stream reach but observed only 20 individuals during 41 person-hours (11.7 hellbenders per search day) over a 6-month period (Trauth et al. 1992, pp. 84-85). This 6-month survey included the two sites surveyed in the early to mid-1980s in which surveyors captured 370 hellbenders, along with eight additional sites upstream and downstream (Peterson et al. 1988, pp. 291-303; Trauth et al. 1992, p. 83). No size class information is available, although the large sizes of captures reported in Peterson et al. (1988, p. 294) may be indicative of a population experiencing little recruitment. Researchers with Arkansas State University surveyed the Spring River from autumn 2003 through winter 2004, performing 74 hours of search effort and found only 12 Ozark Hellbenders (3.9 hellbenders per search day) (Hiler 2005, p. 186). Nine of these animals exhibited severe physical abnormalities and were removed from the river to be housed at the Mammoth Spring National Fish Hatchery but have since died. All nine have since died, however, possibly due to water quality issues at the hatchery or from health issues that were observed when they were captured ( i.e., lesions, raw limbs). Arkansas State University researchers found four and one individual during 2005 and 2006 surveys, respectively. Hellbenders have declined in this stream from unknown causes. Possible reasons for the decline include water quality degradation, aquatic vegetation encroachment, collection for scientific purposes, and illegal commercial collection (Irwin 2008b, pers. comm.). Experts estimated the population in the Spring River to be at most 10 individuals, considered the population in this river to be functionally extirpated, and considered there to be minimal possibility of this stream being reinhabited under present conditions because of the magnitude of habitat degradation (Briggler et al. 2007, p. 83; Irwin 2008b, pers. comm.). Eleven Point River—The Eleven Point River, a tributary of the Black River that occurs in Missouri and Arkansas, has been surveyed several times since the 1970s. Wheeler (1999, p. 10) analyzed historical data and reported that in 1978, 87 Ozark Hellbenders were captured in Oregon County, Missouri, over a 3-day period, yielding an average of 29 hellbenders per search day. From 1980 to 1982, 314 hellbenders were captured in the same area in 9 collection days, yielding an average of 35 hellbenders per search day; hellbender body lengths over that period ranged from 4.7 to 17.8 in (119 to 451 mm) (Wheeler 1999, p. 10). In 1988, Peterson et al. (1988, p. 293) captured 211 hellbenders from the Eleven Point River and estimated hellbender density to be approximately one per 65.6 sq ft (20 sq m). Total lengths of these individuals ranged from 4.7 to 17.7 in (120 to 450 mm), with most between 9.8 and 13.8 in (250 and 350 mm). The average number of hellbenders captured per hour was 8.4 and 8.8 for the two sites sampled, or 67 and 70 hellbenders captured per search day (using the search day conversion method presented in the North Fork White River discussion). As noted previously, the abundance of hellbenders per search day is likely an overestimate, and may be better approximated as 35-40 hellbenders per search day since the reported capture rates do not appear to be relative to the number of surveyors. In 1998, Wheeler (1999, p. 10) captured 36 Ozark Hellbenders over 4 days from the same localities as Peterson et al. (1988, p. 292), for an average of nine hellbenders per search day. These hellbenders were larger than those captured previously, with total lengths of 12.8 to 18.0 in (324 to 457 mm), and there were considerably fewer individuals in the smaller size classes. For comparison, a survey of localities in 2005 by Peterson et al. (1988, p. 293) resulted in a total of 31 hellbenders captured and yielded an average of 2.6 hellbenders captured per search day. Population declines and reduced recruitment in the Eleven Point River in Missouri are indicated by the results of survey data (Briggler 2011b, pers. comm.), although hellbenders are consistently reported during surveys in the Eleven Point River in Arkansas (Irwin 2011a, pers. comm.). Recently in Arkansas (2005 and 2007), however, no more than two or three individuals were caught per search day. Specifically, the catch per person-hour in 2005 was 1.1 hellbenders and in 2007 the capture rate was 0.9 hellbenders per person-hour for surveys conducted on the Eleven Point River in Arkansas (Irwin 2008a, pers. comm.). In 2006, hellbender experts estimated the current Eleven Point River population to be 200 individuals in Arkansas and 100 individuals in Missouri (Briggler et al. 2007, p. 83). Current River—The Current River was not surveyed extensively until the 1990s. Nickerson and Mays (1973a, p. 63) reported a large Ozark Hellbender population in this stream, but no numbers were recorded. In 1992, Ziehmer and Johnson (1992, p. 2) found 12 hellbenders in 60 person-hours in Shannon County, Missouri, or approximately 5 hellbenders per search day (using the same search day conversion as presented in the North Fork White River discussion). These individuals ranged in length from 4.5 in (115 mm) to more than 15.0 in (380 mm; maximum length was not reported), with most between 13.0 and 15.0 in (330 and 380 mm). In 1999, 14 hellbenders were collected over 3 collection days (approximately 5 hellbenders per search day), also in Shannon County, Missouri, and the individuals ranged from 14.8 to 20.3 in (375 to 515 mm) in length, with most between 17.7 to 19.7 in (450 to 499 mm) (Wheeler 1999, p. 12). The average size of individuals increased by nearly 4 in (100 mm), and the reported increase in length suggests that recruitment may be absent in this population. In 2005 and 2006, researchers found 22 hellbenders throughout the Current River in 100 hours of searching (equivalent to 5.2 hellbenders per search day). In 2006, hellbender experts estimated the current population in the Current River to be 80 individuals (Briggler et al. 2007, p. 83). Jacks Fork—Jacks Fork, a tributary of the Current River, was initially surveyed for Ozark Hellbenders in 1992 (Ziehmer and Johnson 1992, p. 2). Four hellbenders were collected over 66 person-hours, equating to roughly 1.5 hellbenders per search day. The individuals were large, ranging from 13.0 to 16.9 in (330 to 430 mm) in length. No hellbenders were found during investigations of Jacks Fork in 2003 nor were any found in 2006 during 7 person-hours of searching (Phillips 2010, pers. comm.). Summary of Comments and Recommendations In the proposed rule published on September 8, 2010 (75 FR 54561), we requested that all interested parties submit written comments on the proposal by November 8, 2010. We also contacted appropriate Federal, State, and local agencies; scientific experts; and other interested parties and invited them to comment on the proposal. Newspaper notices inviting general comments were published in the West Plains Daily Quill (West Plains, Missouri), The Times Dispatch (Walnut Ridge, Arkansas), and The News-Leader (Springfield, Missouri). We did not receive any requests for a public hearing. Between October 21, 2010, and October 28, 2010, the Service received five requests to extend the public comment period for an additional 90 days. The reasons for requesting an extension centered on the Service's proposed determination that it was not prudent to designate critical habitat for the Ozark Hellbender. While the requests cited complexities of the issues involved and concerns regarding the water quality in the streams as the basis for an extension, no new information was provided that was not already outlined in the proposed rule. Therefore, we did not extend the public comment period and further delay the listing. We did, however, host a conference call with the requesters to provide information and answer questions regarding the Service's proposal. We received 65 written comments, including comments from 3 peer reviewers. Fifty-seven comments supported the proposed listing; while six comments expressed neither support for, nor opposition to, the proposal. Eight comments supported a “similarity of appearance” listing for the Eastern Hellbender, with three commenters also supporting a separate listing for the Eastern Hellbender. We reviewed all comments we received from the public and peer reviewers for substantive issues and new information regarding the listing of the Ozark Hellbender. All substantive information provided during the comment period has either been incorporated into this final determination or is addressed below. Peer Review In accordance with our peer review policy published on July 1, 1994 (59 FR 34270), we solicited expert opinions from three individuals with scientific expertise that included familiarity with the species and its habitat, the geographic region in which the species occurs, and conservation biology principles. We received responses from all three peer reviewers from whom we requested comments. The peer reviewers generally agreed that the description of the biology and habitat for the species was accurate and based on the best available information. Peer reviewer comments are addressed in the following summary and incorporated into the final rule as appropriate. New and additional information on the biology of the species and its threats was provided and incorporated into the rulemaking as appropriate. In some cases, it has been indicated in the citations by “personal communication” (pers. comm.); while in other cases, the research citation is provided. Peer Reviewer Comments (1) Comment: In the proposed listing, the Service states that Dundee and Dundee (1965) recommended changing the taxonomic status of the Ozark Hellbender from species to subspecies due to the small amount of genetic variation between Ozark and Eastern Hellbenders. Dundee and Dundee (1965) recommended changing the taxonomic status based on morphology and ecology, not genetic variation. Our Response: We corrected this statement and clarified the remaining section on taxonomy to reflect that subsequent genetic analyses further supported the subspecies designation by Dundee and Dundee (1965). (2) Comment: The pathogen Batrachochytrium dendrobatidis has now been confirmed in all continents, including Asia (Goka et al. 2009). Our Response: We reviewed the reference provided by the peer reviewer and have made the correction in this final rule to reflect the entire range of this pathogen. (3) Comment: Two peer reviewers provided comments regarding the reference in the proposed rule to Pfingsten's (1990) caution that the failure to detect larvae could be interpreted to mean that larvae could occur in areas not surveyed. One peer reviewer relayed that two Eastern Hellbender larvae had been captured in Ohio in habitat similar to that occupied by adults. The peer reviewer also commented that a “retrospective” analysis of the data collected by Pfingsten for Eastern Hellbender populations in Ohio provides strong evidence that the lack of detection of a younger size class ( i.e. larvae) was due to the lack of recruitment in most Ohio populations rather than Pfingsten's failure to survey sites occupied by larvae (Lipps 2010, pers. comm.). The peer reviewer suggested that a similar situation or phenomenon was likely responsible for the lack of recruitment in Ozark Hellbender populations (Lipps 2010, pers. comm.). A second peer reviewer provided two arguments supporting the explanation that lack of larvae detection in surveys is due to an actual lack of recruitment and not survey technique. He noted that researchers have searched in several microhabitats (for example, gravel beds, smaller tributaries) in excess of 100 person-hours without detecting the presence of larvae, and that others have found larvae and juveniles of the Eastern Hellbender in the same microhabitats as adults. Our Response: We concur that the inability to detect larval and juvenile hellbenders is not solely a function of survey technique but most likely reflects an actual reduction or lack of recruitment in the populations. Information provided by the peer reviewers and other supporting references have been incorporated into this final rule. (4) Comment: The Service should consider listing pesticides as a potential direct threat to the Ozark Hellbender. The peer reviewer supports this recommendation with several references, including statements in the proposed rule indicating that hellbenders would be vulnerable to multiple chemicals. The peer reviewer also states that pesticide registration and usage is listed as a potential Federal agency action that may require conference or consultation under Available Conservation Measures. Our Response: In testing water samples collected from the North Fork, White, and Eleven Point rivers from 2003-2004, Solis et al. (2007; pp. 430,432) detected only two pesticides: metolachlor and tebuthiuron. Median concentrations of both chemicals were lower than median concentrations detected from 1992-1995 at various sites throughout the Ozark Plateau (Petersen et al. 1998; p. 24). Metolachlor and tebuthiuron concentrations in 2003-2004 were also lower than the Environmental Protection Agency (EPA) aquatic life benchmarks for the protection of aquatic species (U.S. EPA 2011). Atrazine, which can interfere with normal gonadal development and adversely affect fertility (PARC 2007), was not detected in water samples collected during 2003 and 2004 (Solis et al. 2007; pp. 430, 432). While it is possible that atrazine may be present at concentrations below detectable limits and thus potentially affect hellbenders, available data do not support the recommendation that pesticides are a direct threat. (5) Comment: The Service states in the proposed rule that predation by introduced trout cannot be ruled out as a factor affecting the Ozark Hellbender and that it possibly contributes to the observed population declines. However, nonnative fish stocking is not included in the actions that would be reviewable under section 7(a)(2) of the Act or under actions that may require consultation with the Service. The Service should clarify if they lack the authority to review fish stocking in Ozark Hellbender habitat or explain why this action is not included. Our Response: Section 7(a)(2) of the Act requires that each Federal agency insure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of critical habitat of such species. If an agency receives Federal funding for stocking nonnative fish (such as from the Service's Wildlife and Sport Fish Restoration Program), or if this action is authorized by a Federal agency, the Service would work closely with our partners during the section 7(a)(2) consultation process to assess impacts to Ozark Hellbenders and avoid or minimize these impacts. In the proposed rule we provided a limited list of agency actions that may require conference or consultation for the Ozark Hellbender (see Available Conservation Measures). We have modified the list to also include federally funded activities. Because federally funded or authorized activities can include numerous actions, we did not provide a comprehensive list of all actions that may require section 7 consultation. (6) Comment: One reviewer interpreted the Service's “not prudent” finding to indicate that the Service has determined that sections 7(a)(1) and 7(a)(2) of the Act can sufficiently contribute to the conservation and recovery of the Ozark Hellbender without protecting areas outside the geographical area occupied at the time of listing (through designation of critical habitat). The reviewer requested that the Service explain how we will protect areas outside the currently occupied locations if those areas are considered essential to the recovery of the species and critical habitat is not designated. Our Response: As detailed under Benefits to the Species from Critical Habitat Designation, the Service recognizes that in some instances the designation of critical habitat can provide additional protection beyond that which is already provided through the section 7(a)(2) consultation process (see response to Comment 13a for additional information). One of these benefits is the protection of unoccupied habitat considered essential to the recovery of the species. It is necessary, however, to weigh this benefit against the increased threat of illegal collection to the taxa by designating critical habitat. In doing so, the Service believes that the conservation and recovery of Ozark Hellbenders can best be achieved by preventing the illegal removal of animals from the populations, a threat directly resulting from the publication of critical habitat maps and disclosure of specific locations of occupied sites. (7) Comment: The Service includes “flipping large rocks within streams” as an action likely to result in violation of section 9 of the Act. Moving shelter rocks used by hellbenders, even when returned to their original side down, may make the space beneath the rock unsuitable for hellbenders (personal observation by peer reviewer). Despite taking great effort to return rocks to their original positions, disturbing the “seal” of sedimentation around hellbender shelter rocks may result in the space being abandoned by hellbenders and becoming occupied by rock bass and other fish, thereby reducing the amount of suitable habitat available for hellbenders (Horchler 2010, p. 20). The Service should replace the word “flipping” with “disturbing.” Furthermore, under 50 CFR 17.21 and 17.31, it is illegal to pursue or attempt to pursue an endangered species and this language should be included in the list of likely violations of section 9. Our Response: Manipulation of shelter rocks to locate or capture hellbenders would in most cases be in the form of flipping (overturning) rocks. However, within the context of unauthorized destruction or alteration of hellbender habitat (for reasons other than to locate hellbenders), the microhabitat under or around the rock may be altered by disturbances other than just flipping. Therefore, we have replaced the word “flipping” with “disturbing.” In response to the second part of the peer reviewer's comment, in this final rule, we have specifically identified “pursuing, or attempting to pursue” within those actions likely to result in a violation of section 9. (8) Comment: One reviewer noted that many of the factors potentially contributing to hellbender declines may be operating synergistically to reduce survival. The reviewer provides the following examples: (1) Higher water temperatures due to siltation may lead to an environment favorable for pathogens; (2) poor water quality could contribute to lowered immune capabilities of hellbenders and make them more susceptible to infection from pathogens; and (3) reduced body condition due to water quality issues or pathogen infection could result in individuals becoming more vulnerable to predation (similar linkages with pesticides have been shown in other aquatic amphibians). Our Response: Although we lack definitive data to support this assertion, it is likely that effects of some factors may enhance the effects of other impacts. Because this interaction could further contribute to the Ozark Hellbender's decline, we have referenced synergistic effects and cumulative effects under Factor E (Other Natural or Manmade Factors Affecting Its Continued Existence). Public Comments (9) Comment: Several commenters provided supporting data and information regarding the biology, ecology, life history, population estimates, threat factors affecting the Ozark Hellbender, and current conservation efforts. Our Response: We thank all of the commenters for their interest in the conservation of this species and thank those commenters who provided information for our consideration in making this listing determination. Much of the information submitted was duplicative of information contained in the proposed rule; however, some comments contained information that provided additional clarity or support to, but did not substantially change, information already contained in the proposed rule. This information has been incorporated into this final rule, where appropriate. (10) Comment: There was no mention in the proposed rule of other emerging bacterial and viral infections which may cause significant mortality and contribute rangewide to the decline of Ozark Hellbenders. To support this concern, the commenter noted that a flesh-eating bacterium ( Citrobacter sp.) had been identified on an Ozark Hellbender in Missouri, and that symptoms present on the Missouri specimen are present on the majority of hellbenders captured in Arkansas. The commenter also stated that animals infected with Batrachochytrium dendrobatidis (the pathogen which causes amphibian chytrid fungus) may become immunosuppressed and thus more susceptible to these secondary infections. Our Response: During the development of the proposed rule, factors causing the severe abnormalities observed in Ozark Hellbenders were unknown. Since that time, personnel from the Saint Louis Zoo and other hellbender experts have postulated that the abnormalities are likely caused by secondary bacterial and fungal infections (Briggler 2011a, pers. comm.). Therefore, we have incorporated this information into this final rule under Factor C (Disease or Predation). Although evidence is lacking to conclude that Batrachochytrium dendrobatidis (Bd) suppresses the immune response of animals (and thereby increases their vulnerability to secondary infections), we believe that Bd may be contributing to some of the abnormalities exhibited by hellbenders. Not all hellbenders with abnormalities, such as lesions and appendage loss, however, test positive for infection with Bd (Briggler 2011a, pers. comm.). Therefore, we believe there are factors other than amphibian chytrid fungus that cause increased vulnerability of hellbenders to secondary infections and result in abnormalities. (11) Comment: The Service needs to further investigate the threat of trout to larval hellbenders. Our Response: Concern regarding the potential effect of nonnative trout was expressed by multiple commenters. Because nonnative trout are stocked in all rivers that historically and currently contain hellbenders, and because data from Gall (2008, pp. 48-49) indicate that larval Ozark Hellbenders do not recognize trout as predators, we agree that this topic warrants further investigation. Future conservation and recovery efforts for the Ozark Hellbender will include identifying and implementing research projects that will address the role of nonnative trout as a potential factor contributing to the decline of this subspecies. Should results from research studies indicate that nonnative trout are a threat to Ozark Hellbender populations, the Service will work with the States to avoid or minimize these effects. (12) Comment: Several commenters concurred with the Service's decision not to designate critical habitat, citing the threat posed by illegal collection and the pet trade. However, 12 commenters expressed opposition to the Service's proposed determination not to designate critical habitat for the Ozark Hellbender. These comments generally centered on five main topics and are addressed individually below. (12a) Comment: The Service cannot protect the Ozark Hellbender without designating critical habitat. Our Response: Listed species and their habitat are protected by the Endangered Species Act whether or not they are in an area designated as critical habitat. To understand the additional protection that critical habitat may provide to an area, it is necessary to understand the protection afforded to any endangered or threatened species, even if critical habitat is not designated. Section 7(a)(2) of the Act requires Federal agencies to consult with the Service to ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of any listed species or result in the destruction or adverse modification of critical habitat (referred to as the consultation process). In consultations for species with critical habitat, Federal agencies are required to ensure that their activities do not destroy or adversely modify critical habitat. In most instances, particularly in occupied habitat, the species protection benefits provided by the designation of critical habitat largely duplicate those already provided to the species without the designation of critical habitat by the “jeopardy standard.” This is because when the Service evaluates the impacts of activities, we also look at impacts to the species habitat. Despite this overlap, the Service recognizes that, in some instances, designation of critical habitat could provide some benefits to the Ozark Hellbender (as described under Benefits to the Species from Critical Habitat Designation ). These benefits, however, do not outweigh the increased illegal collection that will likely occur if critical habitat maps are published and the specific locations of currently occupied sites are disclosed (see discussion under Increased Threat to the Species Outweighs the Benefits of Critical Habitat Designation). (12b) Comment: Multiple commenters questioned the degree of threat posed by illegal collection and believed that the publication of critical habitat maps would not increase the risk of unauthorized collection. Our Response: Although the black market for smuggling and illegally selling protected reptiles and amphibians is widely recognized by herpetofauna experts and law enforcement officials, we realize that it may be necessary to provide additional information to support our concern. Therefore, we provided instances in this final rule under Factor B (Overutilization for Commercial, Recreational, Scientific, or Educational Purposes) to further evidence the threat of illegal collection, including: (1) A testimonial from an individual who collected more than 100 Ozark Hellbenders from the North Fork of the White River in the 1980s to sell for the pet trade; (2) the citation of two individuals in 1985 by Missouri Department of Conservation Agents for illegally collecting Ozark Hellbenders; (3) information referencing the unauthorized removal of more than 100 Ozark Hellbenders from the Spring River in the 1980s, and (4) recent information demonstrating that a demand for hellbenders still exists. Because Ozark Hellbenders are not uniformly distributed throughout streams in which they occur, collecting is often focused on a known source or site, thereby threatening extirpation of subpopulations at the site. Publication of critical habitat maps would disclose these sites and facilitate removal by collectors. (12c) Comment: Because only adult hellbenders are subject to illegal collection and larval hellbenders occupy separate habitats from adults, designating critical habitat for all life stages will not increase the threat of illegal collection. Our Response: The Service is unaware of any reasons for which nonadult Ozark Hellbenders would not be subject to illegal collection or of any information supporting this assertion. The contention that hellbender larvae drift downstream with the current and occupy different habitats than adults was expressed by several commenters who opposed the Service's proposed determination that designating critical habitat for this species is not prudent. We are not aware of information indicating that larval hellbenders drift downstream or that they occupy separate habitats from adults. On the contrary, the best available information indicates that, while larval hellbenders may occupy different microhabitats than adults (interstices of gravel rather than large cover rocks), larvae occupy the same stream reach segments as adults (Bishop 1941, pp. 48, 52; Nickerson and Mays 1973a, p. 12; Nickerson et al. 2003, pp. 624-625, 627; Briggler 2010c, pers. comm.; Horchler 2010, pers. comm.; Lipps 2010, pers. comm.; Phillips 2010, pers. comm.). Therefore, designating critical habitat for all hellbender life stages would not prevent unauthorized collecting. (12d) Comment: The locations of hellbender sites are already available to the public; therefore, publishing critical habitat maps would not increase the threat of illegal collection. Our Response: Information currently available to the public is limited and reveals only a small proportion of the total number of sites occupied by Ozark Hellbenders. The designation of critical habitat would result in publishing in the Federal Register precise information about the species and its habitat requirements, where it is found, and maps with geographic coordinates for all occupied locations. The Service is already aware of instances in which the publication of locality information for occupied sites resulted in the removal of almost all individuals from the location. Thus, publishing locations of the remaining occupied sites would only further facilitate illegal collection. (12e) Comment: The habitat of the Ozark Hellbender does not comprise discrete points along the streams, but rather its habitat comprises stream reaches. Therefore, the Service can avoid disclosing exact locations to the public by designating large segments as critical habitat in streams occupied by Ozark Hellbenders. One commenter further noted that the Service has designated large stream reaches for the Niangua darter and the Topeka shiner. Our Response: When designating critical habitat, the Service must determine—based on the best available scientific information—the physical and biological features that are essential to the conservation of a species and which may require special management considerations or protection. Essential physical and biological features are specific habitat components that enable a species to fulfill its life cycle needs. Appropriate cover rocks or other crevices are necessary features to fulfill the life cycle needs of the Ozark Hellbender because they provide protection and nesting habitat. However, unlike the habitat for Niangua darters and the Topeka shiner, stream reaches containing suitable habitat for the Ozark Hellbender are not continuous. Areas with suitable habitat typically range from 100 to 400 yards (91 to 366 meters (m)) in length, and subpopulations within each river system are often separated by miles (kilometers) of unsuitable habitat (data from mark-recapture studies indicate that hellbenders rarely move between sites (Irwin 2009, pers. comm., Briggler 2010b, pers. comm.)). Therefore, by mapping the critical habitat and describing the physical and biological features essential to the conservation of the species, the Service would disclose the specific location of occupied sites and subject the hellbenders to collection. (13) Comment: It is our understanding that the Saint Louis Zoo is currently engaged in propagation efforts and that the Missouri Department of Conservation plans to release captive-reared hellbenders into the Eleven Point River. This effort only addresses the Eleven Point River and not the Current River or the North Fork of the White River. In addition, we are concerned that these augmentation efforts will not be successful. Our Response: Results from genetic studies (Crowhurst et al. 2011; pp. 640-643; Sabatino and Routman 2009; pp. 1239-1240, 1244) indicate that mixing Ozark Hellbenders among rivers could cause an outbreeding depression, or the reduction in fitness of offspring because of the genetic differences between parents. For this reason, it is unlikely that captive-reared individuals will be released into rivers other than those from which the eggs were collected. To date, the Missouri Department of Conservation has collected Ozark Hellbender eggs from the North Fork White River and the Eleven Point River, but has been unable to locate eggs from the Current River. Therefore, releases of captive-reared individuals are planned only for those rivers from which eggs have been collected (North Fork White River and Eleven Point River). Specific areas where augmentation or reintroductions will occur, however, have yet to be identified. Such propagation efforts will be identified in the development of a future approved Federal recovery plan for the species that will be developed through cooperative partnerships with the Ozark Hellbender Work Group and other potentially affected Federal, State, and private entities. Regarding the predicted success of propagation efforts, the Service believes that captive propagation efforts will likely be necessary to conserve and recover the Ozark Hellbender, until causes for the lack of recruitment in the wild can be definitively identified and addressed. When eggs are collected in the wild, larvae can be hatched and reared at significantly higher survivorship rates than those estimated from the wild. When individuals are reared to larger sizes and then released, substantially more hellbenders can survive to maturity and contribute to the population. Summary of Changes From Proposed Rule We fully considered comments from the public and peer reviewers on the proposed rule to develop this final listing of the Ozark Hellbender. This final rule incorporates changes to our proposed listing based on comments received that are discussed above and on newly available scientific and commercial information. Reviewers generally commented that the proposed rule was thorough and comprehensive. We made some technical corrections based on new, although limited, information. Based on comments we received during the public comment period, we also included additional information to provide further evidence of the threat of illegal collection. Information received supports the Service's decision to list the Ozark Hellbender as endangered. Summary of Factors Affecting the Species Section 4 of the Act and its implementing regulations (50 CFR part 424) set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in combination. Each of these factors is discussed below. A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range One of the most likely causes of the decline of the Ozark Hellbender in the White River system in Missouri and Arkansas is habitat degradation resulting from impoundments, ore and gravel mining, sedimentation, nutrient runoff, and nest site disturbance from recreational uses of the rivers (Williams et al. 1981, p. 99; LaClaire 1993, pp. 4-5). Both hellbender subspecies are habitat specialists that depend on consistent levels of dissolved oxygen, temperature, and flow (Williams et al. 1981, p. 97). Therefore, even minor alterations to stream habitat are likely to be detrimental to hellbender populations. Impoundments Impoundments impact stream habitat in many ways. When a dam is built on a free-flowing stream, riffle and run habitats are converted to lentic (still), deep-water habitat. As a result, surface water temperatures tend to increase, and dissolved oxygen levels tend to decrease (Allan and Castillo 2007, pp. 97-98, 323-324). Hellbenders depend upon highly vascularized lateral skin folds for respiration. Therefore, lakes and reservoirs are unsuitable habitat for Ozark Hellbenders, because these areas have lower oxygen levels and higher water temperatures (Williams et al. 1981, p. 97; LaClaire 1993, p. 5) than do fast-flowing, cool-water stream habitats. Impoundments also fragment hellbender habitat, blocking the flow of immigration and emigration between populations (Dodd 1997, p. 178). The resulting small, isolated populations are more susceptible to environmental perturbation and demographic stochasticity, both of which can lead to local extinction (Wyman 1990, p. 351). In the upper White River, construction of Beaver, Table Rock, Bull Shoals, and Norfork dams in the 1940s and 1950s destroyed the potential hellbender habitat downstream of the impoundments and effectively isolated Ozark Hellbender populations. Norfork Dam was constructed on the North Fork in 1944 and has isolated Ozark Hellbender populations in Bryant Creek from those in the North Fork. Furthermore, populations downstream of Beaver, Table Rock, Bull Shoals, and Norfork dams were likely extirpated due to hypolimnetic releases from the reservoir. Hypolimnetic releases are cooler than normal stream temperatures because they are from a layer of water that is below the thermocline, and the water from this layer typically has reduced oxygen levels because it is noncirculating or does not “turn over” to the surface. The tailwater zones below dams also experience extreme water level fluctuations and scouring for several miles downstream. This can impact hellbender populations by washing out the pebbles and cobbles used as cover by juveniles and by creating unpredictable habitat conditions outside the Ozark Hellbender's normal range of tolerance. Impoundments can also affect hellbender habitat upstream by increasing sedimentation during periods of heavy rain because the flow of water is impeded by the presence of the reservoir. In 2008 and 2011, heavy rains and flooding resulted in an increase in water levels in excess of 10 to 15 feet (ft) (3 to 5 meters (m)) and significantly reduced flow velocity (Briggler 2011d, pers. comm.; Crabill 2011b, pers. obs.). Deposition of gravel from the 2008 flood event removed an estimated 30 percent of the available cover rocks and habitat at one of the most abundant Ozark Hellbender sites; while flooding in 2011 removed an additional 50 percent of the habitat at this site (Briggler 2011d, pers. comm.). During high water levels, Ozark Hellbenders at sites upstream of the reservoirs are also exposed to increased predation pressure by large predatory fishes. The increased water levels allow fish to expand upstream of the reservoir and have been observed in large numbers at upstream Ozark Hellbender sites (Roberts 2011, pers. comm.). The increased abundance of large predatory fish, such as brown trout and striped bass, at sites upstream of Norfork Reservoir has even been noted by private landowners near these sites (Anon. 2010, pers. comm.). Mining Gravel mining, which continues to occur in a number of streams within the range of the Ozark Hellbender, has directly contributed to Ozark Hellbender habitat alteration and loss. Gravel mining, also referred to as dredging, results in stream instability, both up and downstream of the dredged portion (Box and Mossa 1999, pp. 103-104). Head cutting, in which the increase in transport capacity of a dredged stream causes severe erosion and degradation upstream, results in extensive bank erosion and increased turbidity (Allan and Castillo 2007, p. 331). Reaches downstream of the dredged stream reach often experience aggradation (raised stream bed from sediment build up) as the sediment transport capacity of the stream is reduced (Box and Mossa 1999, p. 104). Gravel mining physically disturbs hellbender habitat in dredged areas, and associated silt plumes can impact various aspects of the hellbender's life requisites (nesting habitat, prey, dissolved oxygen for egg development). In addition, these effects reduce crayfish populations, which are the primary prey species for Ozark Hellbenders. Because noncommercial gravel mining is not regulated by the States or by the U.S. Army Corps of Engineers, it is difficult to determine the extent of gravel mining within southern Missouri and northern Arkansas. However, an aerial survey conducted in 2001 reported an estimated 12 and 41 active mining sites in the North Fork of the White River and Current River watersheds, respectively (no data were reported for watersheds of the Eleven Point or Spring rivers) (Noell 2003, p. 7). Portions of the Ozark Plateau have a history of being major producers of lead and zinc, and some mining activity still occurs in the southeastern Ozarks, although at levels that are lower than those recorded historically. Results of a U.S. Geological Survey (USGS) water quality study conducted from 1992 to 1995 in the Ozark Plateau (Peterson et al. 1998, pp. 12-13) revealed that concentrations of lead and zinc in bed sediment and fish tissue were substantially higher at sites with historical or active mining activity. These concentrations were high enough to suggest adverse biological effects, such as reduced enzyme activity or death of aquatic organisms. Because hellbenders have highly permeable skin and obtain most of their oxygen through subcutaneous respiration, they are particularly susceptible to absorbing contaminants such as lead and zinc. Furthermore, because Ozark Hellbenders are long lived, they may be at higher risk of bioaccumulation of harmful chemicals (Peterson et al. 1998, pp. 12-13). Although mining for lead and zinc no longer occurs within the range of the Ozark Hellbender, Petersen et al. (1998, p. 12) determined that elevated concentrations of lead and zinc were still present in the streams where mining occurred historically. Although it is possible for these metals to be transported and diluted, they will not degrade over time; therefore, it is likely that lead and zinc concentrations found more than 10 years ago in these rivers would remain at similar concentrations today (Mosby 2008, pers. comm.). In addition, there are historical lead and zinc mining sites that are near Ozark Hellbender populations on the North Fork in Ozark County, Missouri (Mosby 2008, pers. comm.). Increased lead and zinc contamination input to the Current River by way of the active Sweetwater Mine on Adair Creek in Reynolds County, Missouri, is a potential future risk. Adair Creek is a tributary of Logan Creek, a losing stream (loses water as it flows downhill) connected to Blue Spring, which discharges to the Current River. Although lead and zinc contaminants have been found in Logan Creek, there is no evidence that contaminants from Sweetwater Mine have migrated to Blue Spring. However, if the Sweetwater Mine's current tailings dam on Adair Creek were to fail, large concentrations of lead and zinc would be added to Blue Spring and the Current River (Mosby 2008, pers. comm.). Although not common, failures of tailings mines have occurred on six occasions in Missouri since 1940, with several releasing tailings into nearby drainages or creeks (USCOLD 1994, pp. 99-144). Water Quality Despite the claim by some that many Ozark streams outwardly appear pristine, Harvey (1980, pp. 53-60) clearly demonstrated that various sources of pollution exist in the ground water in the Springfield and Salem plateaus of southern Missouri. Water in the Ozark Plateaus is contaminated by nutrients from increased human waste (in part due to rapid urbanization and increased numbers of septic systems), fertilizers (including land application of chicken litter (poultry manure, bedding material, and wasted feed)), logging, and expanded industrial agricultural practices such as concentrated animal feeding operations (Petersen et al. 1998, p. 6). This contamination was evidenced when water samples from the North Fork White and Eleven Point rivers in 2003-2004 contained concentrations of total phosphorus and total nitrogen exceeding the U.S. Environmental Protection Agency (EPA) recommended criteria two-thirds of the time (Solis et al. 2007, pp. 430-431). Agricultural land and livestock production comprises a large percentage of the land use within the Ozark Hellbender range and is a continuing source of contamination (Wheeler et al. 2003, p. 155). Missouri is the second largest beef cattle-producing State in the nation, with the majority of animal units produced in the Ozarks. Both Arkansas and Missouri are leading States in poultry production. The National Water-Quality Assessment data collected in the Ozarks in 1992-1995 from wells and springs indicated that nitrate concentrations were strongly associated with the percentage of mostly agricultural land near the wells or springs (Petersen et al. 1998, p. 8). Although nitrogen and phosphorus are essential plant nutrients that are found naturally in streams, elevated concentrations of these nutrients can cause increased growth of algae and aquatic plants in many streams and are detrimental to aquatic biota (Petersen et al. 1998, p. 6). Increased levels of nitrates (nitrate is a compound of nitrogen and oxygen and usually the most abundant form of nitrogen in the water) can also affect amphibians by inhibiting growth, decreasing survivability, and impairing their immune systems (Marco et al. 1999, p. 2837; Rouse et al. 1999, p. 801; Ortiz et al. 2004, pp. 235-236; Earl and Whiteman 2009, 1334-1335). Increased recreational use (such as from canoeing, kayaking, rafting, inner tube floating, and small horsepower motor boating) also impacts the water and habitat quality in rivers inhabited by the Ozark Hellbender. From 2003 to 2008, the Missouri Department of Natural Resources included an 8-mi (13-km) stretch of the Jacks Fork River in the U.S. EPA's 303(d) list of impaired waters not meeting water quality standards for organic wastes (fecal coliform). Likely sources of the contamination include runoff from a commercial horse trail ride outfitter, horse stream crossings, and effluent from campground pit-toilets (Davis and Richards 2002, pp. 1, 3, and 36). The 303(d) list included additional rivers inhabited by Ozark Hellbenders. A 21-mi (34-km) stretch of the Eleven Point River was listed as impaired due to unacceptable levels of chlorine and atmospheric deposition of mercury. Increased mercury levels have been implicated as a potential cause in the decline of other aquatic amphibians, such as the northern dusky salamander ( Desmognathus fuscus fuscus; Bank et al. 2006, pp. 234-236). Water quality monitoring on both the North Fork White and Eleven Point Rivers in Missouri detected estrogenic compounds that have been demonstrated to adversely impact aquatic organisms, although concentrations were lower than those shown to adversely affect aquatic organisms (Solis et al. 2007, p. 430). Nevertheless, this evidence indicates that hellbenders in the North Fork White and Eleven Point Rivers in Missouri are exposed to a variety of organic chemicals with potential estrogenic activity, and the total effect of these chemicals remains unknown. The Spring River has also suffered from many water quality perturbations over recent decades. In the late 1980s, the West Plains (Missouri) wastewater treatment plant failed, depositing all stored waste into the recharge area for the Spring River. In addition, the majority of the Ozarks region in Missouri and Arkansas is composed of karst topography (caves, springs, sinkholes, and losing streams), which can further facilitate the transport of potential contaminants. Siltation Sediment inputs from land use activities have contributed to, and continue to contribute to, habitat degradation. Hellbenders are intolerant of sedimentation and turbidity (Nickerson and Mays 1973a, pp. 55-56), which can impact them in several ways: (1) Sediment deposition on cover rocks reduces or removes suitable habitat for adults and can cover and suffocate eggs. (2) Sediment fills interstitial spaces in pebble or cobble beds, reducing suitable habitat for larvae and subadults (FISRWG 1998, chapter 3, pp. 19, 25). (3) Suspended sediment loads can cause water temperatures to increase, and cause more particles to absorb heat, thereby reducing dissolved oxygen levels (Allan and Castillo 2007, pp. 323-324). (4) Sedimentation can impede the movement of individuals and colonization of new habitat (Routman 1993, p. 412). (5) The Ozark Hellbender's highly permeable skin causes them to be negatively affected by sedimentation. Various chemicals, such as pesticides, bind to silt particles and become suspended in the water column when flushed into a stream. The hellbender's permeable skin can allow direct exposure to these chemicals, which can be toxic (Wheeler et al. 1999, pp. 1-2). (6) Sedimentation may result in a decline of prey abundance by embedding cover rocks. Timber harvest and associated activities (construction and increased use of unpaved roads, skid trails, and fire breaks) are prominent in many areas within the range of the Ozark Hellbender and increase terrestrial erosion and sedimentation into streams. Peak stream flows often rise in watersheds with timber harvesting activities, due in part to compacted soils resulting from construction of roads and landings (where products are sorted and loaded for transportation) and vegetation removal (Allan and Castillo 2007, p. 332; Box and Mossa 1999, pp. 102-103). The cumulative effects of timber harvest on sedimentation rates may last for a couple of decades, even after harvest practices have ceased in the area (Frissell 1997, pp. 102-104). In addition to those constructed for timber harvest, other roads which are improperly designed and maintained can cause marginally stable slopes to fail, and also capture surface runoff and channel it directly into streams (Allan and Castillo 2007, pp. 321-322, 340). Erosion from roads contributes more sediment than the land harvested for timber (Box and Mossa 1999, p. 102). Unrestricted cattle access to streams increases erosion and subsequent sediment loads (Clary and Kinney 2002, p. 145). This is particularly a concern for the Eleven Point River in Arkansas (Irwin 2008b, pers. comm.). Disturbance Habitat disturbance affects hellbender survival in multiple rivers. Most rivers and streams inhabited by hellbenders are extremely popular with canoeists, kayakers, rafters, inner tube floaters, or operators of low-horsepower motorboats. Canoe, kayak, and motor and jet boat traffic continues to increase on the Jacks Fork, Current, Eleven Point, and North Fork Rivers. On the North Fork River, an average of five canoes per weekday were observed in 1998, and in 2004, that figure increased to 21 canoes per weekday (Pitt 2005, pers. comm.). Hellbenders encountered with gashes in their heads suggest that watercraft traffic likely impacts these animals. New roads, boat ramps, and other river access points have been constructed, which lead to increased river access and increased disturbance to hellbenders (Briggler et al. 2007, p. 64). Off-road vehicle (ORV) recreation is also widespread throughout the Ozarks region. ORVs frequently cross rivers inhabited by hellbenders and are driven in riverbeds where the water is shallow enough to enable this form of recreation. The force delivered by a boat or ORV hitting a rock could easily injure or kill a hellbender, in addition to displacing or disrupting cover rocks. ORV activity also increases erosion and sedimentation by exposing bare erodible soils in areas with frequent activity. The practice of removing large rocks and boulders (by hand, machinery, or dynamite) to reduce damage to canoes is common on many hellbender streams (Nickerson and Mays 1973a, p. 56; Wheeler et al. 1999, p. 4). It has been reported that rocks are possibly removed from streams for home landscaping projects (Briggler et al. 2007, p. 62), although data to support this assertion is lacking. Rock turning and flipping is also done by crayfish hunters, herpetofauna enthusiasts, and researchers (Briggler et al. 2007, pp. 61 and 66). The areas under these large rocks are important habitat for cover and nest sites; therefore, overturning or removing these rocks can diminish available cover and nest sites for hellbenders. Summary of Habitat Destruction and Modification The threats to the Ozark Hellbender from habitat destruction and modification are occurring throughout the entire range of the subspecies. These threats include impoundments, mining, water quality degradation, siltation, and disturbance from recreational activities. The effects of impoundments on Ozark Hellbenders are significant because impoundments alter both upstream and downstream habitat directly, isolate populations, change water temperatures and flows below reservoirs, and increase exposure to predatory fish immediately upstream of the impoundments. Remaining Ozark Hellbender populations are small and isolated, in part due to increased impoundments over time, making hellbenders vulnerable to individual catastrophic events and reducing the likelihood of recolonization after localized extirpations. Habitat destruction and modification from siltation and water quality degradation present a significant and immediate threat to the Ozark Hellbender. Siltation and water quality degradation are caused by human and livestock wastes, agricultural runoff, mine waste, and activities related to timber harvesting. Increased siltation may affect hellbenders in a variety of ways, such as suffocating eggs, eliminating suitable habitat for all life stages, reducing dissolved oxygen levels, increasing contaminants (that bind to sediments), and reducing prey populations. Increased nitrate levels, along with other contaminants from agricultural runoff and increased urbanization, have been detected in hellbender streams. These contaminants not only pose a threat directly to the Ozark Hellbender but also to the aquatic ecosystems upon which this species depends. Pressure from recreational uses (for example, boat traffic, horseback riding, and ORV use) in streams inhabited by Ozark Hellbenders has increased substantially on an annual basis, directly disturbing the habitat. Most hellbender rivers are popular with canoeists, kayakers, rafters, inner tube floaters, and motorboat operators. Removing large rocks and boulders to reduce damage to canoes is a common practice. Gardeners remove rocks for use in landscaping. Crayfish hunters, herpetofauna enthusiasts, and independent researchers (without scientific permits) turn and flip rocks. This disturbance is significant because areas under large rocks are important habitat for cover and nest sites; therefore, overturning and removing these rocks reduces available cover and nest sites for hellbenders. The threats of rock removal and overturning are expected to continue or even increase as these recreational activities grow in popularity. B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes Anecdotal reports and other information indicate that Ozark Hellbenders have been collected for commercial and scientific purposes (Trauth et al. 1992, p. 85; Nickerson and Briggler 2007, pp. 208-209). Although commercial collecting of Ozark Hellbenders has never been permitted by the Arkansas Game and Fish Commission (Irwin 2011b, pers. comm.) nor by the Missouri Department of Conservation (Briggler 2011a, pers. comm.), Nickerson and Briggler (2007, pp. 207-212) determined that large numbers of Ozark Hellbenders have been sold for the pet trade. Because of their protected status in Missouri and Arkansas, any actions involving interstate or foreign commerce of Ozark Hellbenders collected from these States would also be prohibited by the Federal Lacey Act (16 U.S.C. 3371-3378). In Arkansas, hellbenders may be collected with a scientific collecting permit from the AGFC; however, no permits are being issued currently or are anticipated to be issued in the future because the State acknowledges the severely imperiled status of the subspecies (Irwin 2008b, pers. comm.). Missouri imposed a moratorium on hellbender scientific collecting from 1991 to 1996 and has since issued only limited numbers of scientific collecting permits for research (Horner 2008, pers. comm.). Despite these restrictions, unauthorized collecting for the pet trade remains a threat throughout the range because of the willingness of individuals to collect hellbenders illegally (Briggler 2011a, pers. comm.). The illegal and legal collection of hellbenders for research purposes, museum collections, zoological exhibits, and the pet trade has undoubtedly been a contributing factor to hellbender declines. Nickerson and Briggler (2007, pp. 208-211) documented the removal of 558 hellbenders (approximately 300 animals illegally) from the North Fork White River from 1969 to 1989. At least 100 of these were collected in the mid-1980s by individuals from Alabama (Figg 1992, pers. comm.). One of these collectors contacted the Missouri Department of Conservation in 1992 out of remorse and provided details about collecting the hellbenders (Figg 1992, pers. comm.). According to the individual, animals were exported to Japan and labeled as Eastern Hellbenders because Ozark Hellbenders were protected. The individual also relayed that he knew where to search for hellbenders by reading the published literature. In 1985, Missouri Department of Conservation agents apprehended two other individuals illegally collecting Ozark Hellbenders, among other protected species, from the North Fork White River (McNair 2011, pers. comm.). The two individuals were cited and fined for “possession of a protected species.” Anecdotal information suggests unauthorized collection of Ozark Hellbenders on the Spring River in Arkansas contributed to the recent population crash, as reaches of the Spring River that formerly contained 35 to 40 hellbenders have had no individuals present for more than 10 years (Irwin 2008b, pers. comm.). The decline is linked to unauthorized collecting because Ozark Hellbenders were located in one small, easily accessible area of the Spring River, and no other event (such as a storm or chemical spill) had occurred in that area that would explain such a rapid decline (Irwin 2008b, pers. comm.). At another Spring River site, personnel from a local canoe rental reported that commercial collectors took more than 100 Ozark Hellbenders in 2 days (Trauth et al. 1992, p. 85), which also likely impacted the population. Amphibians such as the hellbender, a relatively slow-moving, aquatic species, may be collected with little effort, making them even more susceptible to this threat. While large collecting events appear to have occurred primarily in the 1980s, the unauthorized collection of hellbenders for the pet trade remains a major concern. In 2001, an advertisement in a Buffalo, New York, newspaper was selling hellbenders for $50 each (Mayasich et al. 2003, p. 20). In 2003, a pet dealer in Florida posted an Internet ad that offered “top dollar” for large numbers of hellbenders, wanted in groups of at least 100 (Briggler 2007, pers. comm.). Also in 2003, a person in Pennsylvania had an Internet posting stating specifically that an Ozark Hellbender was wanted, no matter the price or regulatory consequence (Briggler 2007, pers. comm.); while in 2010 a person posted an Internet ad looking for wholesale lots of hellbenders (Briggler 2010a, pers. comm.). At the 2005 Hellbender Symposium, it was announced that U.S. hellbenders were found for sale in Japanese pet stores, which is likely the largest market for this species (Briggler 2005, pers. comm.). Further evidence of the current demand for hellbenders overseas includes an Eastern Hellbender declared for export to Europe in 2010 (Tabor 2010, pers. comm.) and a hellbender (subspecies not specified) declared in 2005 for export to Japan (LEMIS 2008). The Law Enforcement Management Information System (LEMIS) is the Service's law enforcement data system and includes information on imported and exported wildlife. Numbers provided by LEMIS declarations reports, however, can differ greatly from actual export numbers when animals are collected illegally and not declared. As Ozark Hellbenders become rarer, their market value is likely to increase. In fact, listing the subspecies as endangered may also enhance the subspecies potential commercial value as the rarity of the subspecies is made public. Unlike many U.S. species listed under the Act, the Ozark Hellbender has commercial trade value. Due to the market demand and the apparent willingness of individuals to collect hellbenders illegally, we believe that any action that publicly discloses the location of hellbenders (such as publication of specific critical habitat maps or locations) puts the species in further peril. For example, due to the threat of unauthorized collection and trade, the Missouri Department of Conservation and Arkansas Game and Fish Commission have implemented extraordinary measures to control and restrict information on the locations of Ozark Hellbenders and thus no longer make location and survey information readily available to the public. Recreational fishing may also negatively impact Ozark Hellbender populations due to animosity towards hellbenders, which some anglers believe to be poisonous and to interfere with fish production (Gates et al. 1985, p. 18). In addition, there are unpublished reports of hellbenders accidentally killed by frog or fish gigging (spearing), when a hellbender may get speared inadvertently (Nickerson and Briggler 2007, pp. 209, 212). The MDC reports that gigging popularity and pressure have increased, which increases the threat to hellbenders during the breeding season when they tend to move greater distances and congregate in small groups where they are an easy target for giggers (Nickerson and Briggler 2007, p. 212). The gigging season for various species of suckers spans the reproductive season of the Ozark Hellbender in the North Fork White River and also overlaps that of the hellbender in other river basins. The sucker gigging season opens September 15, during the peak breeding period when hellbenders are most active and, therefore, most exposed. Gigging is popular in hellbender streams to such a degree that marks are often noticed on the bedrock and the river bottom from giggers' spears (Briggler 2007, pers. comm.). Although the chance of finding a gigged hellbender can be limited (due to presence of scavengers, the fast decomposition rate of amphibians, and the possibility of giggers removing the specimen), two gigged hellbenders were found along the stream bank on the North Fork White River in 2004 (Huang 2007, pers. comm.). In their studies of Missouri hellbenders, Nickerson and Mays (1973a, p. 56) found dead gigged specimens, and they reference data showing how susceptible the species is to this threat. Ozark Hellbenders are sometimes unintentionally caught by anglers. However, catching hellbenders while fishing is not a frequent occurrence and is not believed to be a significant threat to the species, especially if anglers follow instructions posted by the Missouri Department of Conservation to remove the hook or cut the fishing line and return the hellbender to the stream (Briggler 2009, pers. comm.). Summary of Overutilization for Commercial, Recreational, Scientific, or Educational Purposes The Ozark Hellbender is a rare and unique amphibian that has experienced extensive collection from the wild for various reasons. Due to the continued decline of the Ozark Hellbender and the history of its collection, State agencies in Missouri and Arkansas have implemented measures to reduce the threat of collection. These measures include moratoriums on issuance of scientific collecting permits; prohibiting the collection, possession, and sale of hellbenders under appropriate State wildlife statutes; and controlling information on the location of hellbenders. The unauthorized collection of Ozark Hellbenders for illegal commercial sale in the pet trade, however, continues to be a significant threat. C. Disease or Predation Disease (Chytridiomycosis) Background—Chytridiomycosis is a highly infectious amphibian disease caused by the pathogen Batrachochytrium dendrobatidis (Bd, or amphibian chytrid fungus), and has been demonstrated to infect and kill all life stages of an increasing number of amphibian species worldwide (Berger et al. 1998, pp. 9031-9036). The Ozark Hellbender is now included on the ever-increasing global list of amphibian species potentially affected by this fatal pathogen (Speare and Berger 2011, pp. 1-9). The chytrid fungus attacks the keratinized tissue of amphibians' skin, which can lead to clinical signs of disease presence, such as thickened epidermis, lesions, body swelling, lethargy, abnormal posture, loss of righting reflex, and death (Daszak et al. 1999, pp. 737-738; Bosch et al. 2001, p. 331; Carey et al. 2003, p. 130). It is believed that the fungus originated from Africa with the African clawed frog ( Xenopus laevis ), used throughout the United States in the 1930s and 1940s for pregnancy testing. This pathogen is now found on all continents including Asia, where it was recently documented (Weldon et al. 2004, pp. 2100-2105; Speare and Berger 2005, pp. 1-9; Goka et al. 2009, pp. 4765-4767). Currently, there are two theories on the development of the Bd as a global amphibian pathogen. One theory is that the fungus is not a new pathogen, but has increased in virulence or in host susceptibility caused by other factors (Berger et al. 1998, p. 9036). The other, more widely supported theory is that Bd is an introduced species whose spread has been described as an epidemic `wave-like' front (Lips et al. 2006, pp. 3166-3169; Morehouse et al. 2003, p. 400). B. dendrobatidis lives in aquatic systems in which it `swims' (using spores) through the water and reproduces asexually. The fungus develops most rapidly at 73.4 °F (23 °C) in culture, with slower growth rate at 82.4 °F (28 °C) and reversible stop of growth at 84.2 °F (29 °C; Daszak et al. 1999, p. 741). The temperatures in Ozark streams are ideal for the spread and persistence of this pathogen. Based on U.S. Geological Survey water data from 1996-2006, the maximum temperature of these hellbender streams is 77.0 to 80.6 °F (25 to 27 °C), although the average water temperature over one year (for Eleven Point, Current, and North Fork White River) is approximately 59.0 to 60.8 °F (15 to 16 °C)(Barr 2007, pers. comm.). Persistence of Bd may be further enhanced by saprophytic development (obtaining nourishment from dead or decaying material in water; Daszak et al. 1999, p. 740). Johnson and Speare (2003, pp. 923-924) concluded that the fungus can survive saprophytically outside the amphibian host for up to 7 weeks in lake water and up to 3 to 4 weeks in tap water. Further, Carey et al. (2003, p. 130) stated that amphibians can be infected when placed either in water containing zoospores that were placed specifically in the water, or in water from which infected animals have been recently removed. The possibility that Bd can develop for even a short period of time outside the amphibian host may greatly increase its impact and accelerate host population declines (Carey et al. 2003, p. 130). Also, the possibility of long-term survival of the pathogen as a saprophyte may explain the lack of recolonization of streams from which amphibians, such as the Ozark Hellbender, have been extirpated (Daszak et al. 1999, p. 740). Moreover, hellbenders that are not already infected with Bd are continually at risk because temperatures are ideal for the persistence of the fungus in the water (without a host) for a long period. Habitat specializations and a variety of underlying predisposing environmental factors may make an animal more vulnerable to exposure to the pathogen, especially for species such as the Ozark Hellbender that carry out their life cycle in aquatic rather than terrestrial habitats (Carey et al. 2003, p. 131). Since the Ozark Hellbender lives in an aquatic system throughout its entire life, there is no possibility for relief from this fungus. Climate change is one of the environmental factors that has been indicated as a key promoter in the spread of the Bd pathogen (Pounds et al. 2006, pp. 161-167). Rachowicz et al. (2006, pp. 1676-1682) found that chytridiomycosis was implicated in the local extirpations of two species of frog, and they conclude with high confidence that large-scale warming was the key factor in the disappearances of these two species. Although environmental factors (for example, increased UV-B, chemical pollution, climate change) may predispose amphibian populations to pathogens, evidence suggests that cofactors are not required for chytridiomycosis to cause mass amphibian deaths (Daszak et al. 1999, p. 741). Overall, chytridiomycosis has been implicated in local population extirpations, sustained population declines, and possibly species extinctions for many amphibian species (Berger et al. 1998, pp. 9031-9036; Bosch et al. 2001, pp. 331-337). Chytrid fungi are the best supported pathogens related to amphibian declines, with more than 93 species worldwide affected as of 2005 (Collins and Storfer 2003, pp. 89-98; Daszak et al. 2003, pp. 141-150; Speare and Berger 2005, p. 1). For example, in surveys conducted by Lips et al. (2006, pp. 3165-3166) in Costa Rica and Panama, during only a few months of surveying, frog and salamander species richness and amphibian density declined by more than 60 percent and 90 percent, respectively. The declines were attributed to the prevalence of chytrid fungus in amphibian habitats (Lips et al. 2006, pp. 3165-3166). Disease in captive hellbenders —The St. Louis Zoo maintains a captive population of Ozark and Eastern Hellbenders. In March 2006, there was a power outage in the Zoo's herpetarium, including the area where the hellbenders are held. Soon after the power outage, which may have stressed the hellbenders, possibly reducing their immunity, several hellbenders were observed “with substrate (rocks) sticking to the skin and many were floating” (Duncan 2007, pers. comm.). More than 75 percent of the captive population whose death occurred from March 2006 through April 2007 (59 individuals) likely resulted either directly or indirectly from Bd (Duncan 2007, pers. comm.). Disease in wild hellbenders —As a result of the mortalities in the St. Louis Zoo hellbender population, in 2006 the Missouri Department of Conservation began testing wild hellbenders in Missouri for infection by the pathogen. All Ozark Hellbender streams surveyed had individual hellbenders that tested positive for the pathogen (Briggler 2008b, pers. comm.). Data from 2006 and 2007 show that, for the presence of B. dendrobatidis within the Current River, 20 percent of the population was positive (heavily positive in a few locations, indicating higher concentrations of the fungus); within the Eleven Point River (Missouri and Arkansas), 16 percent was positive (positives spread throughout river); and within the North Fork of the White River, 15 percent was positive (positives spread throughout river) (Briggler 2008b, pers. comm.). These results indicate the minimum number of infected individuals because polymerase chain reaction (PCR) tests for B. dendrobatidis may produce false negative results if the infection is localized in different tissues than were analyzed (Beard and O'Neill 2005, p. 594). The only Ozark Hellbender river not surveyed for the pathogen was the Spring River, where the subspecies is considered functionally extirpated (Irwin 2008a, pers. comm.). During future surveys, all animals encountered (new and recaptures) will be tested for the presence of B. dendrobatidis. The immediacy of the threat from chytridiomycosis has been significantly heightened since the Bd pathogen has been found to occur in all known extant populations of the Ozark Hellbender. Exact effects of the fungus on Ozark Hellbender populations remains unknown, but infected individuals of other amphibian species have experienced decreased growth rates (Davidson et al. 2007, p. 1773) and reduced survivability (Pilliod et al. 2010, pp. 1264-1265). Hellbenders may be particularly sensitive to thickening of the epidermis caused by Bd (Daszak et al. 1999, pp. 737-738) as more than 90 percent of their oxygen is obtained through cutaneous respiration (Guimond and Hutchison, p. 1263). Abnormalities Wheeler et al. (2002, pp. 250-251) investigated morphological aberrations in the Ozark Hellbender over a 10-year period. They obtained deformity data from salamanders that were examined during population and distributional surveys in the Eleven Point River, North Fork of the White River, and Spring River dating back to 1990. They reported a variety of abnormal limb structures, including missing toes, feet, and limbs. Additional abnormalities encountered include epidermal lesions, blindness, missing eyes, and bifurcated limbs. Three hellbenders were documented with tumors on their bodies in the Spring River in Arkansas. Briggler (2011b, pers. comm.) is evaluating and compiling additional information on these abnormalities and lesions, including the frequency of occurrence. Several hellbenders with these abnormalities were x-rayed and are being analyzed by Jeff Briggler, Missouri Department of Conservation. One hellbender with extreme abnormalities (all limbs missing) was euthanized and sent to the USGS National Wildlife Health Center for necropsy, where the conclusive cause for the individual's missing limbs and digits could not be determined. In 2004, 72 percent of Ozark Hellbenders captured had abnormalities present. For reference, 49 percent of Eastern Hellbenders captured in Missouri had abnormalities (Briggler 2007, pers. comm.). In 2006, 90 percent of Ozark Hellbenders surveyed from the Eleven Point River (Missouri), 73 percent from the Current River, and 67 percent from the North Fork of the White River had abnormalities (Briggler 2007, pers. comm.). In general, abnormalities in Ozark Hellbenders are becoming increasingly common and severe, often to a level that the animals are near death (for example, missing digits on all or most limbs, missing all or most limbs; Briggler 2007, pers. comm.). Most, if not all, hellbenders collected in the past decade from the Spring River have had some type of major malformity or lesions (Davidson 2008, pers. comm.). In fact, a hellbender found in the Spring River in 2004 was missing all four feet and was covered in lesions and a fungal growth externally and inside its mouth; this animal died within 15 minutes of capture (Davidson 2008, pers. comm.). The current belief is that secondary bacterial and fungal infections are causing the observed abnormalities on Ozark Hellbenders (Briggler 2011a, pers. comm.). While these pathogens likely naturally occur on the animals, it appears that some unknown factor is increasing the hellbenders' susceptibility to these infections. In hellbenders infected with Bd, there may be a connection between the chytrid fungus and presence of abnormalities such as lesions, digit and appendage loss, and epidermal sloughing. Although evidence is lacking to conclude that infection by Bd causes immunosuppression, it has been hypothesized that the pathogen increases the vulnerability of hellbenders to secondary bacterial and fungal infections and thus is associated with the abnormalities (Irwin 2010, pers. comm.). However, not all hellbenders exhibiting the abnormalities described above test positive for infection by the fungus. Therefore, while the Bd pathogen may cause some hellbenders to be more susceptible to other infections, including those responsible for lesions and appendage loss, it appears that additional unknown factors are underlying the increased vulnerability. While the cause of the observed abnormalities is uncertain, the presence of these physical impairments (and the frequency with which they occur) is likely contributing to Ozark Hellbender declines by reducing survivorship and reproduction. Lesions on the feet and absence of appendages altogether seemingly would reduce motility and foraging ability, and possibly increase vulnerability of hellbenders to predators. Blindness or missing eyes may also decrease survivability; while the overall stress imposed on affected individuals has the potential to reduce breeding activities and thus decrease recruitment. Predation Trout stocking has increased in recent years both in Missouri and Arkansas. While no trout are native to Missouri, both nonnative brown trout ( Salmo trutta ) and nonnative rainbow trout ( Oncorhynchus mykiss ) have been sporadically introduced into Ozark area waters for recreational fishing purposes since the 1800s. The 2003 MDC Trout Management Plan calls for increased levels of stocking as well as increasing the length of cold-water-stream stretches that will be stocked with brown and rainbow trout (Missouri Department of Conservation 2003, pp. 31-32). Nonnative trout are stocked in all rivers that historically and currently contain Ozark Hellbenders ((MDC 2003, pp. 24-26, AGFC 2004, p. 4). In Arkansas, the Arkansas Game and Fish Commission is currently working with the U.S. Army Corps of Engineers to improve cold water releases from mainstem dams along the White River, to improve conditions for trout below the reservoirs (U.S. Army Corps of Engineers 2008, pp. 1-40). In addition, highly predacious tiger muskies (hybrids between Northern pike and muskellunge ( Esox masquinogy x E.lucius ) were introduced into the Spring River in Arkansas in 1989. Introduced fishes have had dramatic negative effects on populations of amphibians throughout North America (Bradford 1989, pp. 776-778; Funk and Dunlap 1999, pp. 1760-1766; Gillespie 2001, pp. 192-196; Pilliod and Peterson 2001, pp. 326-331; Vredenburg 2004, pp. 7648-7649). Rainbow trout and brown trout are considered opportunists in diet, varying their diet with what is available, including larval amphibians (Smith 1985, p. 231; Pflieger 1997, pp. 224-225). Brown trout grow bigger and tolerate a wider range of habitats than do rainbow trout and, therefore, may be a more serious threat to hellbenders, particularly at the larval stage. Dunham et al. (2004, pp. 19-24) assessed the impacts of nonnative trout in headwater ecosystems in western North America. The authors documented at least eight amphibian species that exhibited negative associations with nonnative trout in mountain lakes, specifically regarding the occurrence or abundance of larval life stages of native amphibians. Also, salamander species, such as the long-toed salamander ( Ambystoma macrodactylum ), have been extirpated from waterbodies in high-elevation lakes in western North America due to stocked nonnative trout (Pilliod and Peterson 2001, p. 330). Preliminary data suggest that larval hellbenders from declining populations in Missouri do not recognize brown trout as dangerous predators. In contrast, larvae from more stable southeastern (U.S.) populations that co-occur with native trout show “fright” responses to brown trout (Mathis 2008a, pers. comm.). The failure of hellbender larvae to recognize trout as a threat is likely a nonadaptive response the makes this amphibian more susceptible to predation. A recent study conducted by Gall (2008, pp. 1-86) confirmed results found with this preliminary data on Missouri hellbender populations. Gall (2008, p. 3) examined hellbender (Ozark and eastern) predator-prey interactions by (1) studying the foraging behavior of predatory fish species (native and nonnative (trout)) in response to the presence of hellbender secretion (a potentially noxious chemical cue produced by stressed hellbenders), (2) comparing the number of secretion-soaked food pellets consumed by rainbow and brown trout, and (3) comparing the response of larval hellbenders to chemical stimuli between native predatory fishes and nonnative trout. Gall (2008, pp. 23, 30-31) determined that brown trout were attracted to the secretion emitted by hellbenders, and hellbender secretions were more palatable to brown trout than to rainbow trout. Also, although hellbenders in Missouri exhibited only weak fright responses when exposed to trout stimuli, they responded with strong fright responses to other native predatory fish. Gall (2008, p. 63) suggested that the limited evolutionary history between salmonids (brown and rainbow trout) and hellbenders in Missouri is likely responsible for the weak fright behavior exhibited by hellbenders in response to trout stimuli. Although brown and rainbow trout are a threat to hellbenders, results from this study indicate that rainbow trout are less of an immediate concern than brown trout (Gall 2008, pp. 63-64). This may be due to the difference in diet of the two species; rainbow trout maintain a predominately invertebrate diet throughout their lives and brown trout switch from predominately invertebrate prey to predominately vertebrate prey (including salamanders) at about 8.7 in (22 cm) in length (Gall 2008, p. 60). Gall (2008, p. 63) provided evidence that predation by introduced trout cannot be ruled out as a factor affecting the Ozark Hellbender and possibly contributes to their decline. In addition to brown trout and four other native predatory fish, walleye ( Stizostedion vitreum ) have been stimulated to approach prey more often and faster in the presence of hellbender secretions (Gall 2008, pp. 23-24). Although walleye are native, stocking the species at greater densities than those occurring naturally may increase predation pressures on hellbender larvae stocked in hellbender streams, because walleye share similar activity periods with hellbenders (Mathis 2008b, pers. comm.). Summary of Disease or Predation The discovery of the presence of Batrachochytrium dendrobatidis (Bd, or amphibian chytrid fungus) in 2006 within all remaining populations of the Ozark Hellbender has made increased protection even more important to the persistence of this subspecies (Utrup 2007, pers. comm.). The threat from chytridiomycosis is significant and immediate because: (1) It is proven to be a fatal pathogen to Ozark Hellbenders in captivity, and (2) in the wild, all streams with extant Ozark Hellbender populations have individuals that tested positive for the pathogen (Briggler 2008b, pers. comm.). In addition, although it is unclear if there is a connection to chytridiomycosis, abnormalities found on Ozark Hellbenders are increasingly severe, often to a level short of mortality (Briggler 2008a, pers. comm.). Nonnative trout are stocked in all rivers that historically and currently contain hellbenders in Missouri. Predation of larval hellbenders by nonnative trout and other piscivorous fish possibly contributes to the decline of Ozark Hellbender populations in Missouri and may be a growing concern if predatory fish continue to be stocked (or are stocked in larger numbers) in hellbender streams. D. The Inadequacy of Existing Regulatory Mechanisms In Arkansas, hellbenders may be collected with a scientific collecting permit from the AGFC; however, no permits are anticipated to be issued now or in the future because the State acknowledges the severely imperiled status of the subspecies (Irwin 2008b, pers. comm.). Although Arkansas does not have a State endangered and threatened species list, the State considers the Ozark Hellbender a nongame species and prohibits collection without a permit. The Ozark Hellbender is a State-endangered species in Missouri, which prohibits importation, exportation, transportation, sale, purchase, taking, and possession of the species without a permit. MDC placed a moratorium on hellbender scientific collecting from 1991 to 1996 and has since allowed only limited numbers of scientific collecting permits, and only for those projects contributing to conservation and recovery efforts (Briggler 2011d, pers. comm.). Despite receiving maximum protection by both States, continued unauthorized collecting for the pet trade has been documented and remains a threat throughout the range. State regulations for gigging and for trout stocking do not protect the Ozark Hellbender. The gigging season for various species of suckers spans the reproductive season of the Ozark Hellbender in the North Fork White River and overlaps that of the hellbender in other river basins as well. The sucker gigging season opens annually on September 15, during the peak breeding period when hellbenders are most active and, therefore, most exposed. The 2003 MDC Trout Management Plan calls for increased levels of stocking as well as increasing the length of cold water streams that will be stocked with brown and rainbow trout (MDC 2003, pp. 31-32). In Arkansas, the Arkansas Game and Fish Commission is currently working with the U.S. Army Corps of Engineers to improve cold water releases from mainstem dams along the White River to improve conditions for trout below the reservoirs (U.S. Army Corps of Engineers 2008, pp. 1-40). Clean Water Act Although the Clean Water Act of 1972 (CWA (Pub. L. 92-500)) resulted in an overall gain in water quality in streams, degraded water quality still is a significant factor affecting highly sensitive aquatic organisms such as the Ozark Hellbender because a number of activities responsible for habitat degradation are outside of regulatory oversight. There are no regulatory requirements to implement Best Management Practices (BMPs) to protect water quality from timber management actions. Existing BMPs by the Arkansas Forestry Commission and Missouri Department of Conservation lack mandatory requirements for implementing methods to reduce aquatic resource impacts associated with timber management. Timber harvest activities (for example, logging decks, increased use of unpaved roads, improperly designed and maintained roads, skid trails, fire breaks) may result in erosion and sedimentation. Additionally, there are no laws or regulations that preclude livestock from grazing in riparian corridors and wading in streams and rivers. Nonpoint pollution sources (for example, animal and human waste, agricultural practices, increased road construction) may be causing much of the degraded water quality throughout the Ozark Hellbender's range. The degradation is more apparent in stretches of rivers that are not within federally or State protected lands, such as in the Eleven Point River in Arkansas (Irwin 2008b, pers. comm.). While portions of the Eleven Point River watershed in Missouri are owned by the Federal Government and managed to protect stream and riparian areas from erosion, the entire watershed in Arkansas is privately owned with increased threat from stream bank clearing and unrestricted livestock access, which have an increased effect on remaining Ozark Hellbender populations (Irwin 2008b, pers. comm.). The court's decision in American Mining Congress v. U.S. Army Corps of Engineers (D.D.C. 1997) resulted in the U.S. Army Corps of Engineers deregulating gravel removal activities under section 404 of the CWA. The court found that “de-minimus” or incidental fallback of sand and gravel into the stream from which it was being excavated did not constitute the placement of fill by the mining operation. Hence, the court ruled that the Army Corps of Engineers had exceeded their authority in requiring a permit for this activity. Although these activities no longer require a Clean Water Act 404 permit, commercial operations in Missouri must apply for a State permit through the Missouri Department of Natural Resources Land Reclamation Program. Modifications of stream channels associated with gravel mining, as well as the removal of pebbles and cobble that are important microhabitat for larvae and subadults, possibly contribute to the decline of Ozark Hellbenders in these systems. Lacey Act Under section 3372(a)(1) of the Lacey Act Amendments of 1981 (16 U.S.C. 3371-3378), it is unlawful to import, export, transport, sell, receive, acquire, or purchase any wildlife taken, possessed, transported, or sold in violation of any law, treaty, or regulation of the United States. This prohibition of the Lacey Act would apply in instances where a person engages in a prohibited act with an Ozark Hellbender unlawfully collected from Federal lands, such as those Federal lands within the range of the Ozark Hellbender that are owned and managed by the U.S. Forest Service or the National Park Service. It is unlawful under section 3372(a)(2)(A) of the Lacey Act Amendments of 1981 to import, export, transport, sell, receive, acquire, or purchase in interstate or foreign commerce any wildlife taken, possessed, transported, or sold in violation of any law or regulation of any State. Because it is a violation of Missouri and Arkansas wildlife codes and regulations to sell, purchase, or engage in any actions relating to the commercial trade of Ozark Hellbenders (for example, import, export, ship, or transport), any interstate or foreign commerce of the Ozark Hellbender would result in a violation of the Lacey Act Amendments of 1981. However, if an illegally obtained hellbender is not identified to the Ozark subspecies, it would be difficult for a wildlife inspector to identify it as the prohibited taxon. Although the prohibitions and penalties of the Lacey Act Amendments of 1981 provide some protection for the Ozark Hellbender, this law, by itself, does not adequately prevent or reduce the illegal commercial trade of hellbenders. Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) The unauthorized collection and trade of Ozark Hellbenders within the United States and internationally is of growing concern, particularly as the subspecies' rarity increases and, consequently, commercial value increases. Therefore, concurrent with the proposal to list the Ozark Hellbender as endangered, the Service proposed on September 8, 2010, to include both hellbender subspecies in Appendix III of CITES. CITES is an international agreement between governments with the purpose of ensuring that international trade in wild animals and plants does not threaten their survival. CITES listing of the Ozark Hellbender would aid in curbing unauthorized international trade of hellbenders. CITES can list species in one of three appendices. Appendix I includes species threatened with extinction that are or may be affected by international trade. Appendix II includes species that, although not necessarily threatened with extinction now, may become so unless the trade is strictly controlled. Appendix II also includes species that CITES must regulate so that trade in other listed species may be brought under effective control (for example, because of similarity of appearance between listed species and other species). Appendix III includes native species identified by any Party country that needs to be regulated to prevent or restrict exploitation; under Appendix III, that Party country requests the help of other Parties to monitor and control the trade of that species. Based on the criteria described in 50 CFR 23.90, the Eastern and the Ozark hellbenders qualify for listing in CITES Appendix III. Listing all hellbenders in Appendix III is necessary to allow us to adequately monitor international trade in the taxa; to determine whether exports are occurring legally, with respect to State law; and to determine whether further measures under CITES or other laws are required to conserve this species and its subspecies. Appendix III listings will lend additional support to State wildlife agencies in their efforts to regulate and manage hellbenders, improve data gathering to increase our knowledge of trade in hellbenders, and strengthen State and Federal wildlife enforcement activities to prevent poaching and illegal trade. The final rule for the CITES Appendix III listing is being published concurrently in today's Federal Register . Summary of the Inadequacy of Existing Regulatory Mechanisms Some existing regulatory mechanisms provide protection for the Ozark Hellbender and its habitat. Existing Federal and State water quality laws can be applied to protect water quality in streams occupied by the hellbender, but several factors contributing to degradation of water quality remain outside government regulatory authority. The requirement for a U.S. Army Corps of Engineers dredge and fill permit under section 404 of the Clean Water Act has resulted in an overall gain in water quality. However, ongoing gravel mining in hellbender streams is no longer regulated by the Corps of Engineers under section 404 of the Clean Water Act. Although the Lacey Act provides some protection, the current regulatory mechanisms are not adequate to protect Ozark Hellbenders from unauthorized collection for commercial sale in the pet trade. The Service also finalized listing the Eastern and Ozark hellbender in Appendix III of CITES concurrently in today's Federal Register . Nonetheless, the CITES listing applies only to the export of hellbenders from the United States. Current regulations also do not protect Ozark Hellbenders from gigging by anglers or potential predation by introduced nonnative trout. E. Other Natural or Manmade Factors Affecting Its Continued Existence Small, Isolated Populations —The small size and isolation of remaining populations of the Ozark Hellbender make it vulnerable to extinction due to genetic drift, inbreeding depression, and random or chance events (Smith 1990, pp. 311-321). Inbreeding depression can result in death, decreased fertility, smaller body size, loss of vigor, reduced fitness, and various chromosome abnormalities (Smith 1990, pp. 311-321). Despite any evolutionary adaptations for rarity, habitat loss and degradation increase a species' vulnerability to extinction (Noss and Cooperrider 1994, pp. 58-62). Numerous authors (such as Noss and Cooperrider 1994, pp. 58-62; Thomas 1994, p. 374) have indicated that the probability of extinction increases with decreasing habitat availability. Although changes in the environment may cause populations to fluctuate naturally, small and low-density populations are more likely to fluctuate below a minimum viable population (the minimum or threshold number of individuals needed in a population to persist in a viable state for a given interval) (Gilpin and Soule 1986, pp. 25-33; Shaffer 1981, p. 131; Shaffer and Samson 1985, pp. 148-150). The loss of genetic diversity in Ozark Hellbenders is illustrated by Routman's (1993, pp. 410-415) study, in which hellbender populations from different rivers demonstrated very little within-population variability, and relatively high between-population variability. Due to this population fragmentation, local extirpations cannot be naturally repopulated. Current factors negatively affecting the habitat of the Ozark Hellbender may exacerbate potential problems associated with its low population numbers and the isolation of those small populations from each other, which increases the chances of this subspecies going extinct or making it less able to recover or adapt to catastrophic events. Genetic studies have repeatedly demonstrated very low genetic diversity in hellbender populations, which could contribute to the decline of the species through inbreeding depression (Kucuktas et al. 2001, p. 135). The current combination of population fragmentation, disease, and habitat degradation will prohibit this species from recovering without the intervention of conservation measures designed to facilitate hellbender recovery. Recruitment and Reproductive Capability —The hellbender's late sexual maturity leads to a higher risk of death prior to reproduction and to lengthened generation times (Congdon et al. 1993, p [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2011-25690. Public record. Not legal advice.